1963 Johnson 5.5 Throttle Adjustment

[atucker1]

Hi All,
I just finished a carb rebuild on a 1963 Johnson CD-20 5.5 hp outboard (should be similar to all of the 50s and 60s Evinrude and Johnson 5.5s). I haven't tried running it yet but I put everything back together and it appears that the plate that pushes on the little roller wheel to open the throttle is somehow adjusted wrong.


When the twist grip is set to "slow" or "shift" this plate is nowhere near the throttle roller wheel and the throttle is completely closed.
The roller wheel finally contacts the plate and thus starts opening the throttle when the twist grip is at "start." And, when the twist grip is set to WOT, there is still about 1 cm left on the plate that pushes the roller wheel--the throttle is not fully open and by hand you can push the throttle further. I tried to adjust the plate but it has a limited range of motion with the holes it is set into and currently I cannot adjust it to open the throttle any more. I know this is a confusing description but basically it feels like the whole twist grip and throttle and timing advance mechanism is off. I know the throttle shaft from the tiller has been adjusted before because the tiller broke off at some point. Does anyone have an idea of how to fix this, or is this normal? Thanks for you help.

 

[F_R]

When the twist grip is set to "slow" or "shift" this plate is nowhere near the throttle roller wheel and the throttle is completely closed.

Normal

The roller wheel finally contacts the plate and thus starts opening the throttle when the twist grip is at "start."

Normal

when the twist grip is set to WOT, there is still about 1 cm left on the plate that pushes the roller wheel--the throttle is not fully open and by hand you can push the throttle further

? Are you sure you aren't over-opening the throttle butterfly with your finger--that is, going beyond horizontal?

 

[atucker1]

Hi F_R_, thanks so much for your response. I think you're right on all three counts and that the throttle is correctly adjusted. I took another look at how I had it adjusted, and the roller wheel contacts the plate right at the raised line that I believe is the "timing mark."

So, thinking it was all set, I tried to fire it up in the tank. It basically will not start. I spent probably 30 minutes using all manner of carb settings and it started maybe five or six times, ONLY at full throttle. Moving the throttle the tiniest bit down and it instantly died. And not just like coughed and slowly died--it sounded like someone had cut the spark and the cylinders stopped firing immediately. Most of the time, even if I didn't move the throttle, this would happen after two or three seconds anyway. I tried continuously pumping the fuel primer bulb, but this didn't make a difference. Then, one time it stayed running at full throttle for over a minute, before dying after I tried to mess with the throttle.

I tried adjusting choke, no choke, everywhere from fully closed on low and high speed needles to 2.5 turns open--nothing seemed to help. I understand the initial set point on these should be backed out 1.5 turns on both low and high speed, and I tried many different settings around that area. Nothing seemed to work. I did notice that after it did run, it would never start on the next pull, always a few later, so perhaps too much fuel? But that was even with leaned out carb needles.

Quick background on the motor: I bought it not running and this was exactly what happened when I tried to start it. So, I did a full carb rebuild assuming it was a blocked low speed jet, being super careful to get all passages cleaned out and everything reassembled properly with an OEM OMC carb kit. Now, it's still doing the exact same thing.

I am guessing that since rebuilding the carb did not change (AT ALL! not an ounce of improvement) how it runs, it must be an ignition thing. The only ignition work I've done is replace the spark plugs. So maybe next step is pull the flywheel and check the coils, points, and condensers. I think compression is fine (don't have a gauge) because pulling the starter is a pretty good workout (and yes, I have checked the lower unit shock absorber to make sure that's not creating excess drag).

Anyone have an idea about what is going on? Sorry for the long post but trying to be as detailed as possible. As always, really appreciate everybody's help

 

[racerone]

Weak spark is the main cause of a--- " hard to start condition "----Does spark on this motor jump a gap of 1/4 to 5/16" on both leads , yes ,no or not sure why that is an important test ?

 

[lindy46]

The cam follower (roller) should just begin to open the butterfly in the carb when it hits that mark on the cam. Loosen the cam bolts and adjust in or out to make it so. Those marks on the twist grip are not very accurate. Check under the flywheel for coil condition and clean/set the points.